Design And Simulation Of Drift Control Spray Nozzle

Nowadays China is the highest pesticide use in the whole world. The use of pesticides is helpful for grain production, but excessive use has caused a series of environmental problems. Every year over 1/7 arable land is contaminated by pesticide. Heavily application of chemical pesticides not only caused great harm to the natural environment but also poses a serious threat to human survival and development. The reason why the pesticide was used so much is that the backward spraying method, incomplete application equipment and production process. During the process of application use, pesticide liquid is mostly sprayed by atomization, while spray nozzle has s decisive effect on the liquid atomization, and its performance directly affects the quality of spray, which related to the reliability and economy of the whole plant equipment and system operation.Inner diameter, V-shaped slot angle and relative kerf depth are the important structure factors of nozzle, which have a significant impact to the performance of spray nozzle. According to these three kind of structural factors, nozzles are divided into three groups. In each of group two factors were kept same and change another to study effects of these factors to the atomization performance. The design of nozzle is based on fan-shaped nozzle and three-dimensional models of nozzles are built by Solidworks then select high precision printing materials to make physical production by 3D printing technology.Computational fluid dynamic (CFD) simulation software Fluent is used to simulate the flow field inside of nozzles. During the simulation, Using Gambit which is the pre-processing software of Fluent to get mesh files at first. Then import mesh files to Fluent get pressure field and velocity field images in the center plane of nozzle before setting condition parameter. And then export center line data of nozzles to Matlab to obtain the pressure and velocity curve in order to obtain a better comparison. At last the simulation results show that with the increase of the inner diameter, the internal pressure of the nozzle decreases first and then increases; on the contrary, the internal fluid velocity increases first and then decreases and finally increases again; with increase of V-shaped slot angle, the internal pressure of the nozzle decreases and the internal fluid velocity increases; relative kerf depth has great influence on internal pressure and fluid velocity of nozzles, with increase of relative kerf depth, nozzle internal pressure decreases rapidly and velocity increases significantly.Finally, spray nozzles were installed on the spray test bench to get experimental verification. The spray angle of nozzles were measured by image method, and the flow data of every nozzle was obtained on test bench; Then the uniformity of spray nozzle were detected on V shaped fog tank; at last through the way of grid sampling paper and use pesticide deposition optical measurement to measure the each nozzle spray drift deposition uniformity.